Infection by Gram-negative bacteria such as Extended Spectrum β-lactamase producing (ESBL) Enterobacteriaceae, Pseudomonas aeruginosa, and Acinetobacter baumannii is a major health problem, especially in the case of hospital-acquired infections. In addition, there is an increasing level of resistance to current antibiotic therapies, which severely limits treatment options.
Gram-negative bacteria are unique in that their outer membrane contains lipopolysaccharide (LPS), which is crucial for maintaining membrane integrity, and is essential for bacterial viability (Rev. Biochem 76: 295-329, 2007). The major lipid component of LPS is Lipid A and inhibition of Lipid A biosynthesis is lethal to bacteria. Lipid A synthesized on the cytoplasmic surface of the bacterial inner membrane via a pathway that consists of nine different enzymes. These enzymes are highly conserved in most Gram-negative bacteria. LpxC is the enzyme that catalyzes the first committed step in the Lipid A biosynthetic pathway, the removal of the N-acetyl group of UDP-3-O—(R-3-hydroxymyristoyl)-N-acetylglucosamine. LpxC is a Zn2+ dependent enzyme that has no mammalian homologue, making it a good target for the development of novel antibiotics.